Transmission control system
A gearbox ( 100 ) includes an input shaft ( 105 ), which is connected to a drive source, and a first and a second proportionally controllable shift element (A-F). A method ( 200 ) for open-loop control of the gearbox ( 100 ) includes: determining ( 210 ) an absolute torque demand ( 330 ) on the drive source on the basis of a profile controlled by way of an open-loop system ( 340 ) and a profile controlled by way of a closed-loop system ( 345 ); determining ( 220 ) whether the absolute torque demand ( 330 ) threatens to exceed a predetermined threshold value ( 335 ); and, in response, reducing ( 225 ) the portion controlled by way of the closed-loop system ( 345 ).
1. A method ( 200 ) for open-loop control of a gearbox ( 100 ) that includes an input shaft ( 105 ) connected to a drive source, a first proportionally controllable shift element (A-F) and a second proportionally controllable shift element (A-F), the method ( 200 ) comprising:
determining ( 210 ) an absolute torque demand ( 330 ) on the drive source on the basis of a profile controlled by way of an open-loop system ( 340 ) and a profile controlled by way of a closed-loop system ( 345 );
determining ( 220 ) whether the absolute torque demand ( 330 ) threatens to exceed a predetermined threshold value ( 335 ); and
when the absolute torque demand ( 330 ) threatens to exceed the predetermined threshold value ( 335 ), reducing ( 225 ) the portion of the absolute torque demand ( 330 ) controlled by way of the closed-loop system ( 345 ).
2. The method ( 200 ) of claim 1 , wherein the threshold value ( 335 ) is determined with a characteristic map.
3. The method ( 200 ) of claim 1 , wherein the threshold value ( 335 ) is determined by the drive source.
4. The method ( 200 ) of claim 1 , wherein the reducing ( 225 ) starts when a difference between the absolute torque demand ( 330 ) and the predetermined threshold value ( 335 ) falls below a first predetermined threshold value, and the reducing ( 225 ) terminates when the difference exceeds a second predetermined threshold value, the second threshold value being greater than the first threshold value.
5. The method ( 200 ) of claim 1 , further comprising engaging the second shift element (A-F) when the input shaft ( 105 ) reaches a predetermined rotational speed.
6. A device ( 125 ) for open-loop control of a gearbox ( 100 ) that includes an input shaft ( 105 ) connected to a drive source, a first proportionally controllable shift element (A-F) and a second proportionally controllable shift element (A-F), the device ( 125 ) comprising:
an interface for connection to the drive source;
a processing unit ( 125 ); and
a memory storing computer-executable instructions that, when executed by the processing unit ( 125 ), cause the processing unit ( 125 ) to perform operations comprising
determining an absolute torque demand ( 330 ) on the drive source on the basis of a profile controlled by way of an open-loop system ( 340 ) and a profile controlled by way of a closed-loop system ( 345 ),
determining whether the absolute torque demand ( 330 ) threatens to exceed a predetermined threshold value ( 335 ), and
when the absolute torque demand ( 330 ) threatens to exceed the predetermined threshold value ( 335 ), reducing the portion of the absolute torque demand ( 330 ) controlled by way of the closed-loop system ( 345 ).
7. The device ( 125 ) of claim 6 , further comprising an actuator for engaging the second shift element (A-F) when the input shaft ( 105 ) reaches a predetermined rotational speed.